Housing sealing covers with a shaft bushing, especially for the rear crankshaft seal, are always subject to installation space restriction. The overall height of the housing sealing cover including its fasteners is of decisive importance, but can be influenced essentially only via the thickness of the flange section of the housing sealing cover under the fasteners. For this reason housing sealing covers of drawn sheet metal have become established on the market.
Housing sealing covers for crankshaft penetrations on internal combustion engines can be centered with respect to the crankshaft and engine block via two protruding cylinders which are drawn symmetrically out of the sheet metal carrier element of the housing sealing cover. These protrusions are able to combine a screw penetration and centering function. These centering protrusions, known for example from EP 0 503 143 B1, must be dimensioned such that they can be installed for all tolerance limit positions. This requires a corresponding nominal clearance or nominal play between the protrusions of the housing sealing cover and the corresponding holes of the engine block. EP 0 503 143 B1 furthermore describes that in order to simplify installation, there are protrusions which are arched on at least two screw passage guides and which have three deviations from a circular shape spaced along the periphery of each protrusions, and thus make contact in three spots in the holes of the engine block. The protrusions thus fit without play into the respective holes.